Both revolve around LAW. There are honest law practitioners and dishonest ones in both. The MC wants to punish the criminals in a worst way, more than they deserve kind of way.
Older woman younger man falls in love. The best Noona-Dongseng love story out there. Both dramas have disapproving mothers. Both dramas have the "slow burn" effect. In both dramas, the man is enthusiastic about love while the woman holds back.